The present invention relates to a coupling for forming an optical plug connection between two optical plug connectors, the coupling having a guide sleeve and a sleeve-receiving cage with an interior space for receiving the guide sleeve, the sleeve-receiving cage having plug-in openings which are arranged opposite one another on a longitudinal axis of the sleeve-receiving cage and which serve for the plugging-in of in each case one ferrule of the respective optical plug connector into the guide sleeve in, in each case, one direction parallel to the longitudinal axis, the plug-in openings each being at least regionally surrounded by longitudinal stops of the sleeve-receiving cage for preventing the guide sleeve from being pulled out of the interior space of the sleeve-receiving cage, and the sleeve-receiving cage having two sleeve-receiving cage parts, and the sleeve-receiving cage parts having in each case one detent connection part for forming a detent connection.
In the case of customary commercially available optical plug connectors, provision is generally made for the ferrule to surround at least one light conductor. At the front end of the ferrule, the light conductor is exposed. In order to be able to connect two optical plug connectors to one another such that light signals can be transmitted from the light conductor of one ferrule to the light conductor of the other ferrule, the ferrules and the light conductors arranged therein must be arranged in a very exact manner relative to one another. In general, for this purpose, the ferrules of the two optical plug connectors that are to be connected to one another are connected to one another by means of a corresponding coupling such that the front ends of the ferrules and the light conductors arranged therein bear directly against one another and are correspondingly aligned. To ensure this, in the prior art, couplings for forming an optical plug connection between two optical plug connectors are known which have a sleeve-receiving cage, in the interior space of which there is arranged a guide sleeve. By insertion of the ferrules into the mutually oppositely situated insertion openings of the guide sleeve, the ferrules and thus also the light conductors arranged therein are arranged exactly relative to one another such that the light transmission from one optical plug connector to the other functions. The ferrules of the optical plug connectors are generally mounted in corresponding housings of the optical plug connectors so as to be movable, preferably movable in spring-loaded fashion, such that the guide sleeve can ensure a corresponding alignment of the ferrules relative to one another. In general, the ferrules are held with clamping action in the guide sleeve. Here, in the prior art, it may occur that, when the optical plug connectors are pulled out of the coupling and thus when the ferrules are pulled out of the guide sleeve, the guide sleeve is inadvertently also pulled out of the sleeve-receiving cage. To prevent this, the sleeve-receiving cage has longitudinal stops, normally designed as undercuts, which are intended to retain the ferrules in the interior space of the sleeve-receiving cage. In the case of the coupling and the sleeve-receiving cage being produced in a casting and/or injection-molding process, the production of these longitudinal stops designed as undercuts is generally associated with increased tooling outlay. In order to be able to be demolded, the longitudinal stops or undercuts are often of relatively shallow form, such that, in practice, it is sometimes the case that the guide sleeve is inadvertently pulled together with a ferrule out of the sleeve-receiving cage during the release of the optical plug connection.
In the prior art, couplings of the abovementioned type are also already known in which the sleeve-receiving cage is comprised of two sleeve-receiving cage parts which can be connected to one another by means of a detent connection. In this context, reference is made to WO 2011/128375 A1. In said document, provision is made for the sleeve-receiving cage to be composed of a main part and of a cover which can be slid laterally onto said main part, wherein the cover can be fastened to the main part by means of a detent connection. In the case of the coupling presented in WO 2011/128375 A1, when the cover has been released, the guide sleeve can be inserted into the main part of the sleeve-receiving cage, as can be seen particularly clearly in FIG. 2 of WO 2011/128375 A1.
The possibility of laterally inserting the guide sleeve into the interior space of the sleeve-receiving cage makes it possible for the longitudinal stops to be formed such that the guide sleeve can no longer be inadvertently pulled together with a ferrule out of the sleeve-receiving cage.
This solution, as is realized in WO 2011/128375 A1, can be realized only in the case of couplings in which the sleeve-receiving cage is laterally accessible.